Botulinum neurotoxins (BoNTs) are the most potent natural toxins known (1, 2). These include seven distinct serotypes (A-G) of BoNTs that block acetylcholine release from presynaptic terminals at neuromuscular junctions thereby causing flaccid paralysis (2, 3). The sequences of the seven serotypes of BoNTs are well known in the art. BoNTs are zinc metalloproteases comprising a 50 kD catalytic light chain (LC) linked by disulfide bonds to the 100 kD heavy chain (4). BoNTs transiently and reversibly inhibit synaptic transmission when their light chains cleave one of their target proteins at presynaptic termini. These proteins include Synaptosomal-Associated Protein of 25 kD (SNAP25), vesicle-associated membrane protein (VAMP) and syntaxin (4). The sequences of the BoNT substrates are well known. However, the duration of muscle paralysis varies among the serotypes. Both BoNT/A and BoNT/E target SNAP25. The duration of muscle paralysis from BoNT/A can last for several months whereas the effects of BoNT/E are relatively short-lived (5).